Abstract

The effects of oxygen radicals on sterilization were studied using a surface-wave oxygen plasma. A population of Bacillus stearothermophilusspores was irradiated for or more with oxygen plasma, generated at pressures between 6 and . The decimal reduction value ( value), a measure of the effectiveness of sterilization, was determined to be about . Using only oxygen radicals, excluding all charged particles, the spores were sterilized with a value of after or more of irradiation. On scanning electron microscopy, the length and width of the spores changed significantly due to chemical etching by oxygen radicals.

Received 12 October 2004Accepted 04 April 2005Published online 18 May 2005

Acknowledgments:

This work has been supported by Grants-in-Aid for Scientific Research of JSPS, partly by the regional new consortium projects of METI, and by a Grant of the RSP program of the Shizuoka Organization for Creation of Industries.